royaldeer

This plugin adds an icon to all posts which links to Print-Friendly page with a content of the post. This plugin is very simple to use and very easy to modify, so with a little bit of coding skills you can customize a look of the Print-Friendly page.
“Sites that use the plugin: http://www.zemocigs.com/”
Plugin support: http://www.royaldeerdesign.com/

Printer-Friendly WP

This plugin adds an icon to all posts which links to Print-Friendly page with a content of the post.

Erick Hitter

Oomph, Inc.

Steven Word

Extends WordPress’ template system to support printer-friendly templates for posts, pages, and custom post types. Uses WP standard template naming to support templates on a post-type basis. Supports printing paged posts on single page. Adds nice URLs for printer-friendly pages.
IMPORTANT: There are certain plugins that may interfere with this plugin’s functionality. See the FAQ for more information.

WP Print Friendly

Extends WordPress' template system to support printer-friendly templates. Works with permalink structures to support nice URLs.

Printer-Friendly WP vs WP Print Friendly